City: Minneapolis
State: Minnesota
Owner: International Business Machines
General Contractor: OPUS

Project Description:
Design-build earth retention systems allowed a 50 ft deep excavation to be constructed in downtown Minneapolis, Minnesota.  This excavation required the installation of wall line sheeting consisting of 105 drilled-in soldier beams socketed into rock, 56,000 square feet of lagging, and 388 pressure-injected tiebacks.

In addition, the existing Minneapolis Athletic Club Buildings required extensive underpinning of the shallow footings down to top of rock.  The underpinning consisted of roughly 1,050 feet of hand-dug concrete-filled piers and 30 post-tensioned concrete beam sections.